1. Field of the Invention
The present invention relates to a processing apparatus for forming a metallic material, and more particularly to a processing apparatus capable of improving characteristics of the metal.
2. Description of the Related Art
Metallic materials characteristics change depending on the metal formation process, and component adjusting process is applied as well as heating, cooling, and rolling processes to control those characteristics.
In the case of heating and cooling, crystal, particle diameter of crystal, component distribution of crystal and the like, that depend on characteristics of steel and wires, can be changed by controlling heating patterns and cooling patterns. Among them, considering temperature of cooling patterns when it crosses modification point of metallic material is more important. Further, increasing the cooling speed decrease the crystal particle size and structure of metallic materials, and thereby improves strength and toughness of metallic materials.
It is also known that increasing the cooling speed decrease the crystal particle size, and structure of metallic materials, when molten metals solidify. Especially, rapid cooling forms amorphous metals. Consequently, selecting a cooling process and a coolant for each purpose is important to obtain materials having the required characteristics.
As for coolants, gases, vapor, mist, cold water, distilled water, molten salt, lead, tin, and the like are usually used in order to spray, like a jet, directly onto metallic materials or to store into a container to soak metallic materials.
Other cooling methods are also proposed such that metallic materials are contacted on a metallic coolant roller, and the metallic materials are soaked in liquid metal sodium.
To explain specifically about the heating/cooling process employing liquid metal sodium as a coolant, it is used in a continuous annealing apparatus for the purpose of cooling steel. Therefore, the primary purpose of employing the liquid metal sodium in this annealing apparatus is to exchange heat or to save energy. In this case, the liquid metal sodium is cooled when the steel is in a heating process, and the liquid metal sodium is heated when the steel is in a cooling process, known as counter-flow type heat exchanger. This steel and the liquid metal sodium move in opposite direction. As is obvious from the temperature transition pattern illustrated in FIG. 1, the conventional process aiming heat exchange cannot produce a large temperature difference (xcex94T) between the temperature of steel and the temperature of liquid metal sodium. Thereby, there is a certain limit on cooling speed to form metallic material having required characteristic. Liquid metal sodium is difficult to work with. For example, it explodes on contact with water. Therefore, the use of liquid metal sodium has been reserved for critical applications such as in nuclear power plants.
The present invention has been made in view of the above-mentioned circumstances and is intended to solve the above-mentioned problems. In particular, one purpose of the present invention is to provide a processing apparatus for forming a metallic material capable of providing a metallic material having minute crystal particles and structure. Another purpose of the present invention is to provide a processing apparatus for a metallic material capable of forming amorphous metals from metallic materials.
Additional purposes and advantages of the invention will be apparent to persons skilled in this field from the following description, or may be learned by practice of the invention.
The present invention provides a processing apparatus for forming a metallic material, including: a metallic material heater that heats the metallic material to equal to or higher than the modification point thereof; and a liquid metal sodium supplier that cools the metallic material processed by the metallic material heater to lower than the modification point, by contacting a liquid metal sodium onto the metallic material, wherein the liquid metal sodium flows in the same direction as the metallic material.
In accordance with one aspect of the present invention, the apparatus may further include a cooling tub that stores the liquid metal sodium and soaks the metallic material processed by the liquid metal sodium supplier therein so as to cool the metallic material, and a liquid metal sodium circulator that circulates the liquid metal sodium in the cooling tub. In this case, the apparatus may further include an inert gas spray that sprays inert gas onto the metallic material processed by the cooling tub to remove liquid metal sodium on the metallic material.
The liquid metal sodium may be isolated in a space filled with an inert gas. The cooling tub may be constituted so that the liquid metal sodium supplied from the liquid metal sodium supplier collects in the cooling tub.
The liquid metal sodium circulator may further include an inhalant tube that inhales the liquid metal sodium from a portion adjacent to where the metallic material is pulled out from the cooling tub, an impurity remover that removes impurities from the liquid metal sodium inhaled by the inhalant tube, a liquid metal sodium cooler that cools the liquid metal sodium from which the impurities are removed, and an exhaust tube that returns a cooled liquid metal sodium to the liquid metal sodium supplier.
The metallic material heater may include a heating tub that soaks the metallic materials so as to heat the metallic material.
The metallic material heater may include a melting pot that stores the metallic material in liquid condition. The molten metallic material flows onto a cooling roller that can be rotated, and the liquid metal sodium supplier supplies the liquid metal sodium to the molten metallic material on the cooling roller. In this case, the metallic material thus processed may be an amorphous metal.
The apparatus may include a roller, upstream of the metallic material heater or downstream of the liquid metal sodium supplier, for rolling the metallic material.
The present invention further provides a method for processing a metallic material, including the steps of: heating a metallic material to equal to or higher than the modification point thereof; and cooling the heated metallic material to lower than the modification point, by contacting a liquid metal sodium onto the metallic material, wherein the liquid metal sodium flows in the same direction as the metallic material.